Search Results (294)

Three-dimensional (3D) microscopic imaging is indispensable for fundamental scientific research and clinical medical diagnosis. Given that conventional widefield optical microscopy and standard confocal microscopy fail to realize high-magnification, full-color, real-time stereoscopic imaging simultaneously, we herein propose a single-optical-path 3D microscopic framework enabled by liquid crystal polarization gratings (LCPGs). The LCPG integrated at the sample plane performs polarization-dependent beam splitting to generate paired left and right viewing channels. These two disparity-bearing view channels share a unified imaging optical path compatible with commercial upright microscopes, wherein an active liquid crystal cell modulates temporal view switching for sequential camera acquisition. We further construct a white-light microscopic platform supporting integrated reflection and transmission imaging modes. Two customized LCPGs with lattice periods of 72.6 μm and 56.9 μm are fabricated, offering angular view separations of 0.84° and 1.07°, respectively. Both gratings achieve ±1st-order diffraction efficiencies above 97% with polarization crosstalk not exceeding 0.8%. The developed system acquires paired left-right images with valid binocular disparity, which can be reconstructed into intuitive stereoscopic perceptions via a 3D display monitor. This LCPG-based optical architecture upgrades standard upright microscopes to compact dual-view stereoscopic imaging systems, while fully inheriting the native merits of white-light illumination and high-magnification microscopic observation. Full article

Strawberry is a globally important yet stress-sensitive crop, increasingly threatened by combined abiotic and biotic stresses. Unlike single stresses, combined stresses elicit unique, non-additive responses through complex signaling and gene regulatory networks. This review synthesizes current knowledge on the molecular mechanisms underlying strawberry responses to combined stresses, focusing on signal perception and transduction as well as gene regulation. We examine how combined stresses are perceived by membrane-localized sensors and calcium channels, and how these signals are transduced through MAPK (mitogen-activated protein kinase) cascades, CDPKs (calcium-dependent protein kinases), and hormonal crosstalk involving ABA (abscisic acid), JA (jasmonic acid), and ethylene. At the gene regulation level, we discuss the roles of key transcription factors (WRKY, NAC (NAM, ATAF1, ATAF2 and CUC2), GRAS (GAI-RGA-and-SCR), DREB (Dehydration-Responsive Element-Binding protein), bZIP (basic leucine zipper transcription factor), CAMTA (calmodulin-binding transcription activator), ARF (auxin response factor), and LAV (Leafy Cotyledon2–Abscisic Acid Insensitive3–Val)), transcriptional cascades, epigenetic regulation via DNA methylation, and post-transcriptional (miRNAs such as Fan-miR73) and post-translational (ubiquitination and phosphorylation) control mechanisms. The review also evaluates emerging mitigation strategies informed by these molecular insights, including genomic selection, and explores future directions such as CRISPR (clustered regularly interspaced short palindromic repeats)-based genome editing and multi-omics integration. We conclude that understanding the integrated signaling and gene regulatory networks is essential for developing climate-resilient strawberry cultivars capable of withstanding increasingly complex stress combinations. Full article

The problem of direct inverse optimization of multi-output wavelength division multiplexers (WDMs) on silicon is that these WDMS often exhibit inter-channel crosstalk, making reliable designs difficult to achieve. A cascaded WDM design on a silicon photonics platform is implemented using an inverse design approach. The key idea is to avoid the instability of direct multi-output optimization by sequentially combining several two-output units, thereby realizing a single-input three-output device within a small footprint. Full-wave FDTD simulations show that the first stage achieves effective wavelength separation with high transmission. After cascading two stages, three target wavelengths (1450 nm, 1500 nm, and 1550 nm) are successfully routed to different output ports, with a minimum transmission exceeding 0.71 and inter-channel crosstalk below −9.97 dB, within a total device footprint of 17.745 μm². These results indicate that cascaded inverse design offers a stable and practical solution for multi-channel WDM design on silicon. Full article

Soil salinization has become a major global abiotic threat restricting sustainable viticulture, especially in coastal and inland saline–alkali zones. Unlike cereal crops mainly suffering from sodium toxicity, grapevine (Vitis vinifera L.) is a typical chloride-sensitive woody perennial, subjected to superimposed damages of osmotic stress, ionic imbalance and secondary oxidative injury under saline conditions which severely suppress vegetative growth and degrade berry quality. This review systematically summarizes the multi-layered physiological adaptive mechanisms of grapevine against salt stress, including ion homeostasis maintained by salt overly sensitive (SOS), Na⁺/H⁺ exchanger (NHX) and chloride channel (CLC) transporter families, active accumulation of osmoprotectants, synergistic enzymatic and non-enzymatic antioxidant systems, and phytohormone crosstalk networks formed by endogenous phytohormones (abscisic acid, ABA; jasmonic acid, JA; salicylic acid, SA; brassinosteroid, BR) and small signaling molecules. We further elaborate comprehensive molecular regulatory cascades governing salt tolerance, covering core functional genes for ion transport, master transcription factor families WRKY, MYB, APETALA2/Ethylene Response Factor (AP2/ERF), NAC, basic helix–loop–helix (bHLH) and emerging epigenetic regulatory layers mediated by deoxyribonucleic acid (DNA) methylation, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). In addition, we integrate four categories of field mitigation strategies for saline vineyards: germplasm improvement via salt-tolerant rootstock grafting, rhizosphere soil basal amendment, exogenous biostimulant regulation, and precision agronomic optimization. Current experimental systems do not fully recapitulate complex field combined-stress conditions, as most studies rely on laboratory single-salt stress simulation. Meanwhile, multi-omics, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) gene editing and high-throughput phenotyping tools provide promising approaches to deepen our understanding of grape salt tolerance. This review constructs a comprehensive theoretical framework linking physiological responses, molecular regulatory networks and practical field technologies, offering systematic theoretical references and technical guidance for salt-tolerant germplasm innovation and environmentally sustainable viticulture on saline soils. Full article

Multidimensional metasurfaces provide a promising platform for terahertz (THz) multifunctional devices used in communication, imaging, and sensing. However, many THz multifunctional devices still rely on metallic or periodic metasurfaces, which may suffer from ohmic loss, unwanted diffraction, channel crosstalk, and energy leakage. To address these limitations, we propose an all-dielectric THz metasurface based on a five-fold rotationally symmetric quasicrystalline aperiodic tiling and verify its performance through full-wave electromagnetic simulations. High-resistivity silicon rectangular pillars are used as anisotropic propagation-phase meta-atoms, enabling independent wavefront encoding for two orthogonal linear polarizations within a single aperture. By mapping the x- and y-polarized phase profiles onto the quasicrystalline lattice, the proposed device realizes polarization-multiplexed bifocal focusing with controllable focal positions. Simulation results show high focusing efficiency, low polarization crosstalk, broadband focusing performance, and robustness under oblique incidence. This work provides a compact all-dielectric route for multifunctional THz wavefront control based on polarization multiplexing and quasicrystalline metasurface design. Full article

Conventional Pancharatnam–Berry (PB) phase metasurfaces operate within the two-dimensional SU(2) polarization space of the electric field, fundamentally limiting holographic multiplexing to two independent channels. Here, we propose and numerically demonstrate a four-channel holographic metasurface exploiting the recently discovered Riemann–Silberstein (RS) geometric phase arising from SU(4) polarization evolution in the full electromagnetic field space. The RS vector Ψ = E + icB unifies electric and magnetic fields into a four-dimensional polarization state space. By engineering bianisotropic Huygens meta-atoms with independently controllable electric-dipole orientation angle α and magnetic-dipole orientation angle ψ, four geometric-phase channels—labeled by the joint spin eigenstates |σ,κ⟩∈{|+,+⟩,|+,−⟩,|−,+⟩,|−,−⟩}—are simultaneously addressed from a single aperture. We develop the complete SU(4) transfer-matrix formalism and optimize four quasi-independent phase profiles using an extended Gerchberg–Saxton algorithm with a three-parameter (α,ψ,h) design library, where the pillar height h serves as a third degree of freedom to overcome the linear phase constraint inherent to the two-angle parameterization. Numerical simulations at 0.8 THz demonstrate simultaneous projection of four independent holographic images with mean diffraction efficiency 60.4% and inter-channel crosstalk below 3.2%, doubling the information capacity of conventional dual-channel PB holograms. An intrinsic ~24× common-mode noise suppression arising from electromagnetic duality symmetry is also demonstrated. This work establishes a direct link between fundamental electromagnetic symmetry and high-capacity wavefront engineering. Full article

Perineural invasion (PNI) is a distinct route of cancer spread associated with neuropathic pain, local recurrence, and poor survival across many solid tumours. Increasing evidence shows that PNI is not only a structural pattern of invasion but also a dynamic biological process involving neurodegeneration, nociceptor sensitisation, and marked local immunosuppression. This narrative review synthesises experimental, translational, and clinical data on the molecular, neurological, and immunological mechanisms of PNI in solid malignancies. PNI arises through complex crosstalk between tumour cells, Schwann cells, macrophages, fibroblasts, and neurotrophic pathways, leading to peripheral nerve remodelling, axonal degeneration, and abnormal regeneration. These changes promote neuropathic pain through ion-channel dysregulation, neurotrophin-driven sensitisation, and pathological neuroplasticity. At the same time, PNI creates an immunosuppressive microenvironment enriched in Tregs, M2 macrophages, and myeloid-derived suppressor cells, shaped by cholinergic, adrenergic, and neuropeptidergic signalling, which may contribute to immune exclusion and resistance to immunotherapy. We propose that PNI should be understood as a neuro-immuno-metabolic process and that recognising the PNI–pain–immunosuppression triad may support the development of targeted neuroprotective, analgesic, and immunomodulatory therapies. Full article

Chloride (Cl⁻) is an essential micronutrient for plants that supports multiple physiological functions throughout plant growth and development. Its effects are strongly concentration-dependent: low Cl⁻ availability promotes beneficial physiological processes, whereas excessive accumulation can induce cytotoxicity. In plants, the movement of Cl⁻ across plasma and organellar membranes is primarily mediated by three principal channel and transporter families: chloride channels (CLC), aluminum-activated malate transporters (ALMT), and slow anion channel-associated homologs (SLAC/SLAH). These families differ in gating mechanisms, ion selectivity, transport properties, and subcellular localization. This review synthesizes current knowledge of plant chloride transport proteins, with emphasis on their phylogenetic distribution, structural organization, and functional diversification. We summarize their core physiological roles in stomatal regulation, water-use efficiency, nutrient uptake, ion homeostasis, growth modulation, and abiotic stress tolerance. We also discuss how their activities are regulated by post-translational modifications, notably phosphorylation and dephosphorylation, as well as by ion concentrations, pH shifts, and phytohormone signaling. Unlike earlier reviews that primarily focused on individual transporter families or specific stress responses, this work provides an integrated framework linking structure–function relationships with regulatory networks. It also evaluates recent advances in high-resolution structural biology, electrophysiological approaches, and in vivo imaging techniques. Furthermore, we delineate current technical bottlenecks and unresolved questions, such as the molecular determinants of substrate specificity and potential cross-talk among transporter families, and propose future directions for crop improvement. By integrating structural, physiological, and regulatory perspectives, this review aims to serve as a valuable reference and stimulate interdisciplinary research on plant chloride biology. Full article

Little is known about how nicotinic signalling in human astrocytes may contribute to the functional neurotoxicity of compounds related to tobacco alkaloids and neonicotinoid pesticides. We generated a single-cell Ca²⁺-imaging assay in induced pluripotent stem cell (iPSC)-derived astrocytes, and profiled functional expressions of some neurotoxicologically relevant receptors. Responses to pharmacological tool compounds indicated the expression of nicotinic, muscarinic, purinergic, glutamatergic receptors and voltage-gated Na⁺/Ca²⁺ channels. Closer investigation of the nicotinic system, e.g., using the alpha7 nicotinic acetylcholine receptor (nAChR)-selective positive allosteric modulator PNU-120596 and alpha7-preferring agonist (AR-R17779) demonstrated that Ca²⁺ signals elicited by nicotine and neonicotinoids are dominated by alpha7 nAChRs and depend on the downstream activation of L-type Ca²⁺ channels and tetrodotoxin-sensitive Na⁺ channels. Crosstalk of nAChR activation/desensitization was not observed for the inflammatory response elicited by TNF or for activation of glutamatergic or purinergic signalling. However, pre-stimulation of nAChR by neonicotinoids significantly blunted the response to the neurotransmitter acetylcholine. Comparative experiments in the human neuronal cultures (LUHMES cells) revealed similar potency ranges and pharmacological fingerprints for several neonicotinoids and their human-relevant metabolites descyanothiacloprid and desnitroimidacloprid. The pesticide metabolites showed a high potency, compared with their respective parent compounds. After this basic system characterization, the hitherto data-poor pesticides cycloxaprid and flupyradifurone were comparatively profiled in astrocytic and neuronal test systems. They showed the typical features of alpha7 nAChR agonists. The disruption of cholinergic signalling in astrocytes suggests that neonicotinoids affect not only neurons in human brains. Therefore, future neurotoxicity screening approaches may need to consider astrocyte toxicity. Full article

Human kinematic analysis is an increasingly important tool in biomechanics, human performance, and wearable sensing research. Many emerging sensing modalities utilize custom sensors requiring accurate temporal alignment with ground-truth biomechanical movement data. Optical motion capture systems provide high-fidelity kinematic measurements but operate as closed, self-contained systems, making time synchronization with external sensor data non-trivial, particularly in wireless and mobile contexts. This work presents a wireless analog interface system built using commercially available components that enables alignment between analog sensor data (e.g., from custom wearables and Internet-of-Things devices) and a commercial motion capture system. The proposed architecture consists of a wearable data acquisition node and a receiver node interfaced directly with an optical motion capture system, allowing synchronized recording of analog sensor signals alongside kinematic data. Notably, the system reconstructs signals into the commercial hardware interface rather than relying on triggers or sync outputs, resulting in a single data file containing kinematics and sensor readings. Benchtop testing demonstrated a mean end-to-end frame delay of ~6 ms, with 95% of the sample exhibiting delay within 15 ms. Accounting for the typical offset, this leaves a standard deviation of 4 ms, within one motion capture frame of the true timestamp (at 100 Hz). Voltage reconstruction accuracy was within 30 mV across the tested conditions, with gain compression below 2.7%. Adjacent channel crosstalk remained below −83 dB across all test conditions. The use of commercial off-the-shelf components supports replication and adaptation by other research groups and integration with different optical motion capture systems. Full article

Antigen detection provides rapid and convenient diagnosis of respiratory infections. This study develops an innovative dual-fluorescence aptasensing method based on polydopamine-functionalized MXene (PDA-MXene) for the simultaneous detection of spike protein and hemagglutinin protein. The method employs green- and red-emitting quantum dot (QD) probes as fluorescence reporters, and the PDA-MXene as an effective adsorption and separation substrate. Coupled with a centrifugation-assisted separation strategy, this design method reduces background interference and enhances detection reliability. The method demonstrates good analytical performance, with detection limits of 0.82 ng/mL for spike protein and 2.11 ng/mL for hemagglutinin protein in single-channel mode. The dual-channel mode enables reliable and simultaneous quantification of both target proteins with minimal spectral cross-talk. Furthermore, this method exhibits high specificity against interferents including ions, proteins, and toxins. Artificial saliva, chosen as real sample, is spiked with target proteins to investigate the practical applicability of the method, showing recovery rates for both target proteins between 100 and 114 sensing strategy is simple to operate and allows the detection of new targets by simply replacing the azide-modified aptamer lyophilized powder. It therefore holds promising application for the simultaneous detection of multiple proteins in point-of-care testing and health monitoring fields. Full article

Polarimetric color cameras are a forefront technology that simultaneously captures polarimetric and color information by analyzing polarization states across different color channels, commonly red, green, and blue. In general, each of these color channels can carry different polarization information. Therefore, measuring the polarization Stokes vector at several discrete wavelengths simultaneously and with the highest possible resolution is of interest in multiple research areas. However, when a commercial color polarization sensor is used under simultaneous narrowband RGB illumination mode, its channels cannot be assumed to represent independent wavelength channels. Spectral overlap of the color filters introduces color crosstalk between wavelength-dependent analyzer intensities, which may bias the reconstructed Stokes parameters if it is not corrected before polarimetric inversion. Several methods have been proposed in the literature to address the color crosstalk problem but they typically assume that the polarization state is identical for all wavelengths. This assumption does not generally hold for real samples, which exhibit wavelength-dependent depolarization, retardance, and dichroism. To the best of our knowledge, this is the first work presenting a method that addresses the color crosstalk problem without assuming that the polarization state is identical across all wavelengths. In addition, Fourier domain demosaicking techniques are applied to interpolate the data and reconstruct the images. The present study demonstrates how the proposed method leads to an accurate recovery of chromatic and polarimetric information on both synthetic and real-world datasets. To test our approach, narrowband light beams at three wavelengths (470, 554, 630 nm), with different spatial polarization and degree of linear polarization distributions, have been simulated and validated with simulated and experimental data. The results demonstrate the feasibility of the method for accurate three polarization channels measurements. Full article

The integration density of photonic integrated circuits is fundamentally limited by evanescent field overlap and subsequent inter-channel crosstalk. Layered transition metal dichalcogenides (TMDCs) bypass these confinement constraints through intrinsic optical birefringence and high refractive indices. Here, we report the near-infrared optical constants and waveguide dispersion of molybdenum diselenide (MoSe₂). Ellipsometry performed on centimeter-scale crystals yields an in-plane refractive index of 4.1–4.7 over 1000–2000 nm, with an extinction coefficient close to the sensitivity limit of the fit away from strong excitonic resonances. To validate the anisotropic dielectric tensor at the device scale, scattering-type scanning near-field optical microscopy (s-SNOM) was utilized to map the propagation of transverse-magnetic modes in 235 nm thick exfoliated flakes. Spatial Fourier analysis of the edge-scattered near-field interference yields effective mode indices that precisely match the modeled dispersion. Using the verified dielectric tensor, finite-element simulations demonstrate that single-mode MoSe₂ waveguides optically outperform equivalent tungsten disulfide (WS₂) benchmarks. The enhanced evanescent field suppression in the claddings of MoSe₂ waveguide increases the coupling length by a factor of 3.5, reducing the required routing pitch and enabling a 12.5% direct increase in on-chip integration density. The results identify MoSe₂ as a high-index anisotropic platform for compact waveguiding in the near-infrared. Full article

We present a family of compact, programmable wavelength demultiplexers enabled by an etchless silicon nitride platform integrated with the low-loss phase-change material Sb₂Se₃. Using topology optimization (LumOpt) with a p-norm (p = 2) figure-of-merit defined over a 10 nm bandwidth, we design several devices within a common 24 × 24 μm² design region: single-wavelength routers (1530, 1550, 1570, 1590 nm), two-channel (1550/1570 nm), three-channel (1530/1550/1570 nm), and four-channel (1530–1590 nm) coarse wavelength-division demultiplexers, all sharing the same input/output waveguide configuration. Simulation results show that all devices achieve low insertion loss at target wavelengths (peak transmission better than −1.21 dB across all channels), high average transmission over the respective 10 nm bands (typically within 0.1 dB of the peak), and suppressed crosstalk (worst case below −11.52 dB). Leveraging the reversible amorphous-to-crystalline phase transition of Sb₂Se₃ via laser pulses, all devices support post-fabrication reconfiguration, overcoming the static functionality of conventional etched photonic circuits. This work establishes a scalable, software-defined platform that combines inverse design and phase-change materials for high-density, reconfigurable wavelength-routing photonic integrated circuits. Full article

Single-molecule Förster resonance energy transfer (smFRET) enables direct measurement of nanoscale conformational dynamics and heterogeneity in biomolecules, but quantitative interpretation of smFRET data critically depends on well-controlled excitation geometry, low background fluorescence, robust calibration, and reproducible data-analysis workflows. Prism-based total internal reflection fluorescence (pTIRF) microscopy provides important advantages for such measurements by physically separating excitation and emission paths and generating a highly confined evanescent field, yet practical guidance for implementing reproducible, quantitative pTIRF systems remains fragmented. Here we present a comprehensive, standardized framework for the design, alignment, calibration, validation, and operation of a prism-based TIRF microscope optimized for single-molecule fluorescence measurements. We describe the complete optical architecture for dual-color excitation and detection, establish alignment invariants that ensure reproducible evanescent excitation and stable donor–acceptor channel registration, and detail surface preparation, flow control, and photostabilization strategies required for reliable long-term imaging. Quantitative benchmarking protocols are introduced to evaluate signal-to-noise ratio, photobleaching kinetics, and spectral crosstalk, providing objective criteria for defining optimal operating conditions and instrument performance limits. Finally, we integrate these experimental procedures with an end-to-end single-molecule data-analysis workflow encompassing channel registration, automated and manual trajectory selection, FRET calculation, and kinetic analysis using hidden Markov modeling. The utility of the platform is demonstrated through smFRET measurements of conformational dynamics in a model nucleic acid system. Together, this work provides a reproducible and accessible methodology for implementing prism-based TIRF microscopy as a robust quantitative platform for single-molecule fluorescence studies across a wide range of biomolecular systems. Full article